Transformer protection method and device applied to oiled paper capacitive bushing

Abstract

The invention discloses a transformer protection method and device applied to an oiled paper capacitor type bushing, and relates to the technical field of electric power, and the method comprises the following steps: collecting pressure data and temperature data in the bushing in real time; performing fault analysis according to the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the equipment has a fault or does not have a fault; when the fault analysis result is that the equipment has a fault, a tripping signal is sent out; the tripping signal is used for controlling the transformer of the bushing to perform tripping operation. According to the application, whether the equipment has a fault is judged through the pressure data and the temperature data in the bushing acquired in real time, and the tripping signal is sent out when the equipment has the fault is analyzed, so that the transformer of the bushing is controlled to execute the tripping operation, further expansion of the fault is avoided, and the safety of the equipment and the safety of a related operating environment are guaranteed.

Description

Technical Field

[0001] The present application generally relates to the field of electric power technology, and specifically to a transformer protection method and device applied to an oil-paper capacitor type bushing. Background Art

[0002] Transformer explosion accidents caused by internal faults of oil-paper capacitor bushings frequently occur. The main reason is that when the transformer explodes, the fault is mainly removed by differential protection, and the differential protection mainly relies on the change of current to operate. When a slight discharge fault occurs inside the bushing, the transformer differential protection will not start tripping, and the transformer will continue to operate. Only when the discharge fault continues to expand and eventually causes the bushing to explode, and then causes a grounding fault in the lead, the transformer differential protection can start the tripping procedure and remove the fault.

[0003] However, due to factors such as water ingress into the bushing, serious leakage of insulating oil, aging of the insulating medium, and the presence of conductive impurities inside the bushing, the internal faults of the bushing all start from slight discharge. As the discharge becomes more and more serious, the temperature of the insulating oil inside the bushing rises rapidly, and the internal pressure of the bushing increases rapidly. Finally, when the bushing sealing material is not enough to seal the internal pressure, the bushing will explode. Therefore, we provide a transformer protection method and device applied to oil-paper capacitor bushing to solve the above problems. Summary of the invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a transformer protection method and device for oil-paper capacitor type bushings that can effectively prevent the internal faults of the bushings from further developing and expanding, thereby ensuring the safety of the equipment.

[0005] In a first aspect, the present application provides a transformer protection method applied to an oil-paper capacitor type bushing, comprising the following steps: Collect the pressure and temperature data inside the casing in real time; Performing fault analysis according to the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the device has a fault or the device does not have a fault; When the fault analysis result indicates that a fault exists in the equipment, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

[0006] According to the technical solution provided in the embodiment of the present application, the pressure data is the first pressure value collected at the current moment, and the temperature data is the first temperature value collected at the current moment; Follow these steps to determine the fault analysis results: When the first pressure value is greater than or equal to a set pressure threshold and the first temperature value is greater than or equal to a set temperature threshold, it is determined that the fault analysis result is that the device has a fault; When the first pressure value is less than the set pressure threshold and the first temperature value is less than the set temperature threshold, it is determined that the fault analysis result is that there is no fault in the device; When the first pressure value is greater than or equal to the set pressure threshold or the first temperature value is greater than or equal to the set temperature threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

[0007] According to the technical solution provided in the embodiment of the present application, the pressure data includes at least a first pressure value collected at the current moment and a second pressure value and a third pressure value collected at the previous two moments, and the temperature data includes at least a first temperature value collected at the current moment and a second temperature value and a third temperature value collected at the previous two moments; Follow these steps to determine the fault analysis results: Calculate a first pressure change rate and a second pressure change rate according to the first pressure value, the second pressure value, and the third pressure value; and calculate a first temperature change rate and a second temperature change rate according to the first temperature value, the second temperature value, and the third temperature value; When the first pressure change rate and the second pressure change rate are both greater than or equal to a pressure change threshold and the first temperature change rate and the second temperature change rate are both greater than or equal to a temperature change threshold, it is determined that the fault analysis result is that the device has a fault; When the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate are all less than corresponding change thresholds, it is determined that the fault analysis result is that the device does not have a fault; When at least one of the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate is less than the corresponding change threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued at the same time; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

[0008] According to the technical solution provided in the embodiment of the present application, the following steps are also included: When no trip signal is issued within the preset monitoring time, collecting the fourth pressure value and the fourth temperature value currently inside the casing; A first difference is calculated based on the first pressure value and the fourth pressure value; and a second difference is calculated based on the first temperature value and the fourth temperature value; If the first difference exceeds the pressure deviation range and / or the second difference exceeds the temperature deviation range, the detection device is determined to be abnormal and an alarm signal is issued; the alarm signal is used to remind the operator to replace the detection device.

[0009] According to the technical solution provided in the embodiment of the present application, the following steps are also included: After the trip signal is issued, real-time monitoring is performed to determine whether the transformer performs a trip operation; If the transformer fails to complete the tripping operation within the preset operation time, a troubleshooting signal is issued; the troubleshooting signal is used to prompt the operator to inspect the transformer, and the preset operation time is less than the preset detection time.

[0010] According to the technical solution provided in the embodiment of the present application, the following steps are also included: Acquire a historical data set inside the casing; the historical data set includes historical pressure data and historical temperature data inside the casing collected at multiple historical moments; Calculate the historical pressure standard deviation and the historical temperature standard deviation based on the historical pressure data and the historical temperature data in the historical data set; If the historical pressure standard deviation is greater than the set standard deviation and the historical temperature standard deviation is greater than the set standard deviation, an abnormal warning message is generated, and the set pressure threshold and the set temperature threshold are lowered.

[0011] According to the technical solution provided in the embodiment of the present application, obtaining a historical data set inside the casing includes the following steps: An initial data set inside the casing is obtained, and outliers and missing values ​​in the initial data set are removed to obtain a historical data set.

[0012] According to the technical solution provided in the embodiment of the present application, after the fault analysis result is that the equipment has a fault and before the trip signal is issued, the following steps are also included: Identify whether the transformer differential protection has an abnormal current difference warning, and if the transformer differential protection has no abnormal current difference warning, obtain the current capacitance value and dielectric loss factor; When the capacitance value exceeds the capacitance fluctuation range and / or the dielectric loss factor exceeds the factor fluctuation range, a trip signal is issued.

[0013] In a second aspect, the present application provides a transformer protection device applied to an oil-paper capacitor type bushing, which is used to implement the above-mentioned transformer protection method applied to the oil-paper capacitor type bushing, and the device includes: The first detection module is used to collect the pressure data inside the casing in real time; The second detection module is used to collect temperature data inside the casing in real time; A fault analysis module is used to perform a fault analysis based on the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the equipment has a fault or the equipment does not have a fault; when the fault analysis result is that the equipment has a fault, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

[0014] It can be seen from the above technical solution that the present application has at least the following beneficial effects: The present application provides a transformer protection method applied to an oil-paper capacitor type bushing, which comprises the following steps: real-time acquisition of pressure data and temperature data inside the bushing; performing fault analysis according to the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the equipment has a fault or the equipment does not have a fault; when the fault analysis result is that the equipment has a fault, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

[0015] This application determines whether there is a fault in the equipment through the real-time collected pressure data and temperature data inside the bushing, and sends a trip signal when it is analyzed that there is a fault in the equipment, thereby controlling the transformer of the bushing to perform a trip operation, which helps to avoid further expansion of the fault and ensure the safety of the equipment and related operating environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0017] Figure 1 The figure is a flow chart of a transformer protection method applied to oil-paper capacitor type bushing.

[0018] Figure 2 Flowchart for the first method of determining fault analysis results.

[0019] Figure 3 Flowchart for the second method of determining fault analysis results.

[0020] Figure 4 This is a structural diagram of a transformer protection device used for oil-paper capacitor type bushings.

[0021] Figure 5 This is the structural diagram of the oil-paper capacitor type bushing.

[0022] Numbers in the figure: 1. first detection module; 2. second detection module; 3. fault analysis module; 4. casing; 5. casing oil pillow; 6. first porcelain casing; 7. second porcelain casing; 8. flange; 9. equalizing ring; 10. end screen. DETAILED DESCRIPTION

[0023] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] In order to make the description of the following embodiments clear and concise, a brief introduction to the related technology is first given: Due to factors such as water ingress into the bushing, serious leakage of insulating oil, aging of the insulating medium, and the presence of conductive impurities inside, the internal faults of the bushing all start from slight discharge. As the discharge becomes more and more serious, the temperature of the insulating oil inside the bushing rises rapidly, and the pressure inside the bushing increases rapidly. Finally, when the bushing sealing material is not enough to seal the internal pressure, the bushing will explode. If a slight discharge fault occurs inside the bushing, the transformer differential protection will not operate before the transformer lead is short-circuited to ground. The transformer differential protection will only operate after the bushing explodes and causes the lead to short-circuit to ground. However, at this time, the bushing fault has developed to an uncontrollable stage.

[0026] In order to make the transformer protection method for oil-paper capacitor bushing provided in the embodiment of the present application clearer and easier to understand, the method is introduced below with reference to the accompanying drawings. Figure 1 As shown, the figure is a flow chart of a transformer protection method applied to an oil-paper capacitor type bushing provided in an embodiment of the present application, and the method comprises the following steps: S100, collecting pressure data and temperature data inside the casing in real time.

[0027] Here, the first detection module 1 can be used to collect the pressure data inside the casing in real time, and the second detection module 2 can be used to collect the temperature data inside the casing in real time. The type of the first detection module 1 is, for example, a pressure sensor, and the type of the second detection module 2 is, for example, a temperature sensor.

[0028] S200, performing fault analysis according to the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the device has a fault or the device does not have a fault.

[0029] Pressure data and temperature data are key monitoring indicators that can reflect the actual operating status inside the casing. By analyzing the pressure data and temperature data, the fault analysis results are obtained, and the fault analysis results are used to characterize whether the casing is currently in a normal working state.

[0030] This application provides the following methods to determine the fault analysis results: First way: The pressure data is the first pressure value collected at the current moment, and the temperature data is the first temperature value collected at the current moment; like Figure 2 As shown, determine the fault analysis results according to the following steps: S201. When the first pressure value is greater than or equal to a set pressure threshold and the first temperature value is greater than or equal to a set temperature threshold, it is determined that the fault analysis result is that the device is faulty.

[0031] It should be noted that the set temperature threshold can be set according to actual conditions; the first pressure value is greater than or equal to the set pressure threshold and the first temperature value is greater than or equal to the set temperature threshold, that is, the first pressure value and the first temperature value exceed the corresponding set thresholds at the same time, indicating that some more serious abnormal conditions have occurred inside the equipment, resulting in excessive pressure and temperature. At this time, the fault analysis result is determined to be that the equipment is faulty.

[0032] S202: When the first pressure value is less than the set pressure threshold and the first temperature value is less than the set temperature threshold, it is determined that the fault analysis result is that there is no fault in the device.

[0033] It should be noted that the first pressure value is less than the set pressure threshold and the first temperature value is less than the set temperature threshold, that is, the first pressure value and the first temperature value do not exceed the corresponding set thresholds, indicating that the equipment currently has no abnormal fluctuations and can maintain a normal working state. The pressure and temperature inside the casing can continue to be monitored to timely detect potential abnormal change trends.

[0034] S203. When the first pressure value is greater than or equal to the set pressure threshold or the first temperature value is greater than or equal to the set temperature threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued at the same time; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

[0035] It should be noted that the first pressure value is greater than or equal to the set pressure threshold or the first temperature value is greater than or equal to the set temperature threshold, that is, the first pressure value or the first temperature value exceeds the corresponding set threshold, and the other is less than the corresponding set threshold, indicating that the equipment can currently maintain basic operation, and the overall operating state has not yet reached the severity of being determined as a fault. The fault analysis result is determined to be that there is no fault in the equipment, but at the same time, an alarm signal needs to be issued, and the alarm signal is used to prompt the operator to perform pre-maintenance on the casing based on the abnormal data (the first pressure value or the first temperature value), so as to eliminate possible fault risks in advance, thereby preventing the casing from developing in the direction of failure.

[0036] For example, when When , a trip signal is issued; The data sampling period is , Indicates the current moment, is the first temperature value collected at the current moment, is the first pressure value collected at the current moment, It is used to indicate whether the first temperature value is abnormal. When it is 0, it indicates that there is no abnormality. When it is 1, it indicates that there is an abnormality. It is used to indicate whether there is an abnormality in the first pressure value. When it is 0, it indicates that there is no abnormality, and when it is 1, it indicates that there is an abnormality.

[0037] Second way: The pressure data includes at least the first pressure value collected at the current moment and the second pressure value and the third pressure value collected at the previous two moments, and the temperature data includes at least the first temperature value collected at the current moment and the second temperature value and the third temperature value collected at the previous two moments; here, the second pressure value and the third pressure value collected at the previous two moments are historical pressure data, and the second temperature value and the third temperature value collected at the previous two moments are historical temperature data.

[0038] like Figure 3 As shown, determine the fault analysis results according to the following steps: S204, calculating a first pressure change rate and a second pressure change rate according to the first pressure value, the second pressure value and the third pressure value; and calculating a first temperature change rate and a second temperature change rate according to the first temperature value, the second temperature value and the third temperature value.

[0039] It should be noted that the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate are calculated according to the following formula: , ; , ; in, is the first temperature change rate, is the first temperature value, is the second temperature value, is the data sampling period, is the second temperature change rate, is the third temperature value, is the first pressure change rate, is the first pressure value, is the second pressure value, is the third pressure value.

[0040] S205. When the first pressure change rate and the second pressure change rate are both greater than or equal to the pressure change threshold and the first temperature change rate and the second temperature change rate are both greater than or equal to the temperature change threshold, it is determined that the fault analysis result is that the equipment is faulty.

[0041] It should be noted that the first pressure change rate and the second pressure change rate are both greater than or equal to the pressure change threshold, and the first temperature change rate and the second temperature change rate are both greater than or equal to the temperature change threshold, that is, the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate all exceed the corresponding change thresholds, indicating that there is an abnormal situation inside the equipment. At this time, the fault analysis result is judged that there is a fault in the equipment.

[0042] S206: When the first pressure change rate, the second pressure change rate, the first temperature change rate, and the second temperature change rate are all less than corresponding change thresholds, it is determined that the fault analysis result is that the device does not have a fault.

[0043] It should be noted that the first pressure change rate, the second pressure change rate, the first temperature change rate, and the second temperature change rate are all less than the corresponding change thresholds, indicating that the equipment currently has no abnormal fluctuations and can maintain normal operating conditions. The pressure and temperature inside the casing can continue to be monitored to promptly detect potential abnormal change trends.

[0044] S207. When at least one of the first pressure change rate, the second pressure change rate, the first temperature change rate, and the second temperature change rate is less than the corresponding change threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued at the same time; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

[0045] It should be noted that at least one of the first pressure change rate, the second pressure change rate, the first temperature change rate, and the second temperature change rate is smaller than the corresponding change threshold, that is, at least one change rate is smaller than the corresponding change threshold, and the remaining change rates exceed the corresponding change threshold, indicating that the equipment can currently maintain basic operation, but the equipment has potential hidden dangers, and the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued at the same time. The alarm signal is used to prompt the operator to perform pre-maintenance on the casing based on the abnormal data, eliminate possible fault risks in advance, and thus avoid the casing from developing in the direction of failure.

[0046] For example, when When , a trip signal is issued; in, Indicates the temperature change threshold, Indicates the pressure change threshold.

[0047] The third way: Combine the first method with the second method, first make a judgment according to the first method, and after executing the first method, if the step reaches S202, execute the steps in the second method. The purpose of this analysis method is to analyze the operating status of the equipment more accurately and comprehensively, and then obtain reasonable fault analysis results, and take appropriate follow-up measures to ensure the safe and stable operation of the equipment.

[0048] S300. When the fault analysis result shows that the equipment is faulty, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

[0049] Among them, when it is determined that there is a fault in the equipment, a tripping signal is issued in time and the transformer of the bushing is controlled to perform a tripping operation, which helps to avoid further expansion of the fault and ensure the safety of the equipment and related operating environment. Furthermore, the present application also includes the following steps: When no trip signal is issued within the preset monitoring time, collecting the fourth pressure value and the fourth temperature value currently inside the casing; A first difference is calculated based on the first pressure value and the fourth pressure value; and a second difference is calculated based on the first temperature value and the fourth temperature value; If the first difference exceeds the pressure deviation range and / or the second difference exceeds the temperature deviation range, the detection device is determined to be abnormal and an alarm signal is issued; the alarm signal is used to remind the operator to replace the detection device.

[0050] It should be noted that the preset monitoring time can be set according to actual conditions. If no tripping signal is issued within the preset monitoring time, it means that the equipment is always in normal operation or the detection equipment may be faulty and cannot detect the abnormality of the equipment in time. At this time, it is necessary to use the backup detection equipment to collect the current fourth pressure value and fourth temperature value inside the casing, and calculate the first difference and the second difference. Here, the pressure deviation range is, for example, ±5%, and the temperature deviation range is, for example, ±3°C; if the first difference and the second difference exceed the corresponding deviation range at the same time, or one of the two differences exceeds the corresponding deviation range, it means that the corresponding detection equipment has an abnormality. At this time, an alarm signal needs to be issued to remind the operator to replace the corresponding detection equipment to ensure that the actual operating status of the equipment can be truly reflected to avoid affecting subsequent equipment failure judgment and early warning operations.

[0051] Furthermore, the present application also includes the following steps: When the trip signal is issued, real-time monitoring is performed to see whether the transformer performs the trip operation; If the transformer fails to complete the tripping operation within the preset operation time, a troubleshooting signal is issued; the troubleshooting signal is used to prompt the operator to inspect the transformer, and the preset operation time is less than the preset detection time.

[0052] It should be noted that the preset operation time can be set according to actual needs.

[0053] In order to ensure that the entire fault response mechanism can effectively play a role and protect the safety of the equipment and the entire system, it is necessary to monitor in real time whether the transformer completes the tripping operation on time. If the transformer fails to complete the tripping operation within the preset operation time, it means that the transformer or the equipment around the transformer may be damaged. At this time, a troubleshooting signal is issued to prompt the operator to inspect the transformer to ensure that the transformer completes the tripping operation smoothly.

[0054] Furthermore, the present application also includes the following steps: Obtain a historical data set inside the casing; the historical data set includes historical pressure data and historical temperature data inside the casing collected at multiple historical moments; Here, obtaining the historical data set inside the casing includes the following steps: The initial data set inside the casing is obtained, and the outliers and missing values ​​in the initial data set are removed to obtain the historical data set. Among them, the outliers refer to the data values ​​where equipment failure has occurred or is potentially present, and the missing values ​​refer to the data that is not collected by the detection equipment or is lost during the data transmission process.

[0055] According to the historical pressure data and the historical temperature data in the historical data set, the historical pressure standard deviation and the historical temperature standard deviation are calculated; If the historical pressure standard deviation is greater than the set standard deviation and the historical temperature standard deviation is greater than the set standard deviation, an abnormal warning message is generated and the set pressure threshold and the set temperature threshold are lowered.

[0056] It should be noted that the standard deviation can be set as a reference value that is pre-set based on the reasonable degree of discreteness of pressure and temperature data under normal operating conditions of the equipment.

[0057] If the historical pressure standard deviation is greater than the set standard deviation and the historical temperature standard deviation is greater than the set standard deviation, it means that the dispersion of pressure and temperature data during the past operation of the equipment has exceeded the normal expected range. This may indicate that although the equipment has not yet experienced a real-time fault, there are some potential and unstable factors in the long run. For example, some parts inside the equipment may have gradual problems such as slight wear and aging, which cause the pressure and temperature fluctuations to be more obvious than normal. The purpose of lowering the set pressure threshold and the set temperature threshold is to make the subsequent fault judgment based on real-time collected data more sensitive, and to more easily discover potential abnormal conditions that may develop into actual faults, so as to make the monitoring and protection of the equipment more stringent, so that operators can intervene as early as possible to perform inspections, maintenance and other operations, and try to avoid serious equipment failures in the end, and ensure the stability and reliability of equipment operation.

[0058] If the historical pressure standard deviation is less than the set standard deviation and the historical temperature standard deviation is less than the set standard deviation, no adjustment is required. If the historical pressure standard deviation or the historical temperature standard deviation is less than the corresponding set difference, only the one that does not meet the conditions can be adjusted.

[0059] Furthermore, after the fault analysis result shows that the device has a fault and before the trip signal is issued, the following steps are also included: Identify whether the transformer differential protection has an abnormal current difference warning. If the transformer differential protection has no abnormal current difference warning, obtain the current capacitance value and dielectric loss factor; When the capacitance value exceeds the capacitance fluctuation range and\or the dielectric loss factor exceeds the factor fluctuation range, a trip signal is issued.

[0060] It should be noted that transformer differential protection is one of the important protection mechanisms to ensure safe and stable operation of transformers. Its basic principle is to determine whether there is a fault inside the transformer by comparing the current size and phase information on both sides (or multiple sides, depending on the wiring method of the transformer, etc.) of the transformer. Under normal circumstances, the currents on both sides should satisfy a certain balance relationship, that is, the difference is within a reasonable data range.

[0061] Capacitance value and dielectric loss factor are important indicators reflecting the insulation performance of transformer bushings.

[0062] The transformer differential protection has no abnormal current difference warning, which means that the differential protection has not detected any abnormal current difference for the time being. Then, the current capacitance value and dielectric loss factor are obtained. If the capacitance value exceeds the capacitance fluctuation range and / or the dielectric loss factor exceeds the factor fluctuation range, it means that although the differential protection has not detected any abnormal current difference for the time being, the abnormalities in capacitance and dielectric loss are sufficient to indicate that there are serious problems with the equipment, which may cause serious faults such as insulation breakdown and short circuit, thus causing great harm to the transformer and the entire power system. A trip signal is also needed to cut off the equipment to prevent the fault from further deteriorating.

[0063] like Figure 4 As shown, a transformer protection device applied to an oil-paper capacitor type bushing is used to implement the above-mentioned transformer protection method applied to an oil-paper capacitor type bushing, and the device includes: The first detection module 1 is used to collect the pressure data inside the casing in real time; The second detection module 2 is used to collect temperature data inside the casing in real time; The fault analysis module 3 is used to perform fault analysis based on the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the equipment has a fault or the equipment does not have a fault; when the fault analysis result is that the equipment has a fault, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

[0064] It should be noted that if Figure 5 As shown, the oil-paper capacitor type bushing includes: a bushing 4, a flange 8 is provided on the outer sleeve of the bushing 4, and a first porcelain sleeve 6 is provided at one end of the flange 8, and a second porcelain sleeve 7 is provided at the other end thereof, the first porcelain sleeve 6 and the second porcelain sleeve 7 are both sleeved on the bushing 4, a bushing oil pillow 5 is provided at the free end of the first porcelain sleeve 6, and a pressure equalizing ring 9 is provided at the free end of the second porcelain sleeve 7, an end screen 10, a first detection module 1 and a second detection module 2 are respectively installed at positions of the first porcelain sleeve 6 near the flange 8, and the first detection module 1 and the second detection module 2 are respectively communicatively connected to the fault analysis module 3.

[0065] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A transformer protection method applied to oil-paper capacitor bushing, characterized in that: The following steps are involved: Collect the pressure and temperature data inside the casing in real time; Performing fault analysis according to the pressure data and the temperature data to obtain a fault analysis result; The fault analysis result is that the device has a fault or the device does not have a fault; When the fault analysis result indicates that a fault exists in the equipment, a trip signal is issued; the trip signal is used to control the transformer of the bushing to perform a trip operation.

2. A transformer protection method applied to oil-paper capacitor bushing according to claim 1, characterized in that: The pressure data is a first pressure value collected at the current moment, and the temperature data is a first temperature value collected at the current moment; Follow these steps to determine the fault analysis results: When the first pressure value is greater than or equal to a set pressure threshold and the first temperature value is greater than or equal to a set temperature threshold, it is determined that the fault analysis result is that the device has a fault; When the first pressure value is less than the set pressure threshold and the first temperature value is less than the set temperature threshold, it is determined that the fault analysis result is that there is no fault in the device; When the first pressure value is greater than or equal to the set pressure threshold or the first temperature value is greater than or equal to the set temperature threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

3. A transformer protection method for oil-paper capacitor bushing according to claim 1, characterized in that: The pressure data at least includes a first pressure value collected at the current moment and a second pressure value and a third pressure value collected at the previous two moments; the temperature data at least includes a first temperature value collected at the current moment and a second temperature value and a third temperature value collected at the previous two moments; Follow these steps to determine the fault analysis results: Calculate a first pressure change rate and a second pressure change rate according to the first pressure value, the second pressure value, and the third pressure value; and calculate a first temperature change rate and a second temperature change rate according to the first temperature value, the second temperature value, and the third temperature value; When the first pressure change rate and the second pressure change rate are both greater than or equal to a pressure change threshold and the first temperature change rate and the second temperature change rate are both greater than or equal to a temperature change threshold, it is determined that the fault analysis result is that the device has a fault; When the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate are all less than corresponding change thresholds, it is determined that the fault analysis result is that the device does not have a fault; When at least one of the first pressure change rate, the second pressure change rate, the first temperature change rate and the second temperature change rate is less than the corresponding change threshold, the fault analysis result is determined to be that there is no fault in the equipment, and an alarm signal is issued at the same time; the alarm signal is used to prompt the operator to perform pre-maintenance on the casing.

4. A transformer protection method applied to oil-paper capacitor bushing according to claim 2 or 3, characterized in that: The following steps are also included: When no trip signal is issued within the preset monitoring time, collecting the fourth pressure value and the fourth temperature value currently inside the casing; Calculating a first difference according to the first pressure value and the fourth pressure value; and calculating a second difference value according to the first temperature value and the fourth temperature value; If the first difference exceeds the pressure deviation range and / or the second difference exceeds the temperature deviation range, the detection device is determined to be abnormal and an alarm signal is issued; the alarm signal is used to remind the operator to replace the detection device.

5. A transformer protection method for oil-paper capacitor bushing according to claim 4, characterized in that: The following steps are also included: After the trip signal is issued, real-time monitoring is performed to determine whether the transformer performs a trip operation; If the transformer fails to complete the tripping operation within the preset operation time, a troubleshooting signal is issued; the troubleshooting signal is used to prompt the operator to inspect the transformer, and the preset operation time is less than the preset detection time.

6. A transformer protection method for oil-paper capacitor bushing according to claim 2, characterized in that: The following steps are also included: Acquire a historical data set inside the casing; the historical data set includes historical pressure data and historical temperature data inside the casing collected at multiple historical moments; Calculate the historical pressure standard deviation and the historical temperature standard deviation based on the historical pressure data and the historical temperature data in the historical data set; If the historical pressure standard deviation is greater than the set standard deviation and the historical temperature standard deviation is greater than the set standard deviation, abnormal warning information is generated, and the set pressure threshold and the set temperature threshold are lowered.

7. A transformer protection method for oil-paper capacitor bushing according to claim 6, characterized in that: Obtaining a historical data set inside the casing includes the following steps: An initial data set inside the casing is obtained, and outliers and missing values ​​in the initial data set are removed to obtain a historical data set.

8. A transformer protection method for oil-paper capacitor bushing according to claim 1, characterized in that: After the fault analysis result indicates that the device has a fault and before a trip signal is issued, the following steps are also included: Identify whether the transformer differential protection has an abnormal current difference warning, and if the transformer differential protection has no abnormal current difference warning, obtain the current capacitance value and dielectric loss factor; When the capacitance value exceeds the capacitance fluctuation range and / or the dielectric loss factor exceeds the factor fluctuation range, a trip signal is issued.

9. A transformer protection device applied to an oil-paper capacitor type bushing, used to implement the transformer protection method applied to an oil-paper capacitor type bushing according to any one of claims 1 to 8, characterized in that: The device comprises: A first detection module (1) is used to collect pressure data inside the casing in real time; A second detection module (2) is used to collect temperature data inside the casing in real time; A fault analysis module (3) is used to perform fault analysis based on the pressure data and the temperature data to obtain a fault analysis result; the fault analysis result is that the equipment has a fault or that the equipment does not have a fault; when the fault analysis result is that the equipment has a fault, a trip signal is issued; and the trip signal is used to control the transformer of the bushing to perform a trip operation.

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